6,996 research outputs found
Radii and Binding Energies of Nuclei in the Alpha-Cluster Model
The alpha-cluster model is based on two assumptions that the proton-neutron
pair interactions are responsible for adherence between alpha-clusters and that
the NN-interaction in the alpha-clusters is isospin independent. It allows one
to estimate the Coulomb energy and the short range inter-cluster bond energy in
dependence on the number of clusters. The charge radii are calculated on the
number of alpha-clusters too. Unlike the Weizsacker formula in this model the
binding energies of alpha-clusters and excess neutrons are estimated
separately. The calculated values are in a good agreement with the experimental
data.Comment: Latex2e 2.09, 13 pages, 4 figure
Charge Radii of beta-Stable Nuclei
In previous work it was shown that the radius of nucleus R is determined by
the alpha-cluster structure and can be estimated on the number of
alpha-clusters disregarding to the number of excess neutrons. A hypothesis also
was made that the radius R_m of a beta-stable isotope, which is actually
measured at electron scattering experiments, is determined by the volume
occupied by the matter of the core plus the volume occupied by the peripheral
alpha-clusters. In this paper it is shown that the condition R_m = R restricts
the number of excess neutrons filling the core to provide the beta-stability.
The number of peripheral clusters can vary from 1 to 5 and the value of R for
heavy nuclei almost do not change, whereas the number of excess neutrons should
change with the number of peripheral clusters to get the value of R_m close to
R. It can explain the path of the beta-stability and its width. The radii R_m
of the stable isotopes with 12 =< Z =< 83 and the alpha-decay isotopes with 84
=< Z =< 116 that are stable to beta-decay have been calculated.Comment: Latex2e 2.09, 10 pages, 3 figure
Masses and Radii of the Nuclei with N>=Z in an Alpha-Cluster Model
In the framework of a recently developed alpha-cluster model a nucleus is
represented as a core (alpha-cluster liquid drop with dissolved excess neutron
pairs in it) and a nuclear molecule on its surface. From analysis of
experimental nuclear binding energies one can find the number of alpha-clusters
in the molecule and calculate the nuclear charge radii. It was shown that for
isotopes of one Z with growing A the number of alpha-clusters in the molecule
decreases to three, which corresponds to the nucleus 12C for even Z and 15N for
odd Z, and the specific density of the core binding energy \rho grows and
reaches its saturation value. In this paper it is shown that the value
\rho=2.55 MeV/fm^3 explains the particular number of excess neutrons in stable
nuclei.Comment: 7 pages, 3 eps figures, submitted as a contribution to the
Proceedings of the International Conference, Messina, Italy, October 5-9,
200
isomiR2Function: An integrated workflow for identifying MicroRNA variants in plants
© 2017 Yang, Sablok, Qiao, Nie and Wen. In plants, post transcriptional regulation by non-coding RNAs (ncRNAs), in particular miRNAs (19-24 nt) has been involved in modulating the transcriptional landscape in developmental, biotic and abiotic interactions. In past few years, considerable focus has been leveraged on delineating and deciphering the role of miRNAs and their canonical isomiRs in plants. However, proper classification and accurate prediction of plant isomiRs taking into account the relative features by which we define isomiRs, such as templated or non-templated is still lacking. In the present research, we present isomiR2Function, a standalone easily deployable tool that allows for the robust and high-throughput discovery of templated and non-templated isomiRs. Additionally, isomiR2Function allows for identification of differentially expressed isomiRs and in parallel target prediction based on both transcripts or PARE-Seq either using Targetfinder or Cleaveland. isomiR2Function allows for the functional enrichment of the detected targets using TopGO package. Benchmarking of isomiR2Function revealed highly accurate prediction and classification of isomiRs as compared to the previously developed isomiR prediction tools. Additionally, the downstream implementation of additional features allows isomiR2Function to be classified as a single standalone tool for isomiR profiling from discovery to functional roles. All in all, isomiR2Function allows the streamline processing of the miRNA-seq for the identification and characterization of isomiRs with minimal efforts. isomiR2Function can be accessed through: https://gi thub.com/347033139/isomiR2Function
Resolving singular forces in cavity flow: Multiscale modeling from atoms to millimeters
A multiscale approach for fluid flow is developed that retains an atomistic
description in key regions. The method is applied to a classic problem where
all scales contribute: The force on a moving wall bounding a fluid-filled
cavity. Continuum equations predict an infinite force due to stress
singularities. Following the stress over more than six decades in length in
systems with characteristic scales of millimeters and milliseconds allows us to
resolve the singularities and determine the force for the first time. The
speedup over pure atomistic calculations is more than fourteen orders of
magnitude. We find a universal dependence on the macroscopic Reynolds number,
and large atomistic effects that depend on wall velocity and interactions.Comment: 4 pages,3 figure
Formation and observation of a quasi-two-dimensional electron liquid in epitaxially stabilized SrLaTiO thin films
We report the formation and observation of an electron liquid in
SrLaTiO, the quasi-two-dimensional counterpart of SrTiO,
through reactive molecular-beam epitaxy and {\it in situ} angle-resolved
photoemission spectroscopy. The lowest lying states are found to be comprised
of Ti 3 orbitals, analogous to the LaAlO/SrTiO interface and
exhibit unusually broad features characterized by quantized energy levels and a
reduced Luttinger volume. Using model calculations, we explain these
characteristics through an interplay of disorder and electron-phonon coupling
acting co-operatively at similar energy scales, which provides a possible
mechanism for explaining the low free carrier concentrations observed at
various oxide heterostructures such as the LaAlO/SrTiO interface
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